1. Field of the Invention
The present invention relates to a photographic distortion apparatus for producing a contact copy of a photographic transparency, the copy being shortened or lengthened in one dimension only while the other dimension remains unchanged.
2. Description of the Prior Art
For various applications, it is desirable to alter only one, but not the other dimension of an image. For example, a newspaper might receive an advertising layout which is the correct column width, but is shorter than the intended or available space in the newspaper column. Normal photographic enlargement of the advertisement is not helpful, since this would result in a layout that is the correct length but too wide for the column. In the past, this situation may have required a completely new advertising layout, with concomitantly high cost. An object of the present invention is to provide a photographic distortion apparatus that is useful in such situations to provide a contact copy of a photographic film image in which one dimension of the copy is shortened or lengthened while the other dimension remains unchanged.
Certain photographic distortion devices have been proposed. For example, the photo-composing apparatus shown in the U.S. Pat. No. 3,401,616 to Cross facilitates both single dimension compression of elongation, as well as tilting or other distortion of the original image. The apparatus employs a linearly movable work table that holds the design negative. The table moves on rails past a light source that is projected through a long narrow slit which extends across the work surface of the table. A complex linkage including a swing arm and a slide bar is used to move a photographic film past the light slit, underneath the design negative, at a rate of travel that is different from the negative. As a result, a contact copy is formed that is distorted in accordance with the differential speeds and directions at which the design negative and film are moved past the light slit.
Photographic distortion in one dimension only also is accomplished using the device disclosed in the U.S. Pat. No. 3,445,165 to Dubbs. There, two separate movable mounting frames are used respectively to support the photographic image that is being reproduced and the photosensitive film. Independent drive mechanisms transport the two mounting frames past an illuminated slit at different rates.
Another object of the present invention is to provide a photographic distortion apparatus of simple mechanical design, which does not require mounting tables of frames, nor separate linkages to achieve differential rates of travel for the photographic transparency and film. Thus, an object of the present invention is to provide a mechanically simple distortion apparatus.
A similar objective was achieved by the inventor's Optical Distortion Device which is the subject of U.S. pat. application Ser. No. 523,927, now U.S. Pat. No. 3,967,898. There, the leading edges of the photographic transparency and of the photosensitive sheet respectively were attached to a pair of cylindrical rollers rotatably mounted within a light-proof box. The rollers were driven at different rotational rates by a pair of variable speed synchronous motors. Electrical control was used to vary the speed of one motor with respect to the other so as to control the roller rotation rates, and hence to control the difference in linear speeds at which the transparency and the photosensitive sheet were pulled past a narrow light slit. Unidimensional lengthening or shortening was achieved.
The inventor's aforementioned Optical Distortion Device has the advantage of permitting continuous control over the relative speeds past the slit, and hence of the extent of image enlargement or compression. Another object of the present invention is to provide a photographic distortion apparatus having a simplified mechanical means for achieving such continuous control over the extent of image expansion or compression. Another objective is to provide an apparatus in which the photographic transparency and the film sheet are not attached to the drive rollers, but rather are simply inserted into the apparatus and driven therethrough as the dimension-modified copy is made. The apparatus thus features simplificity of operation.